This invention relates to apparatus for monitoring a condition such as tire pressure including apparatus for remotely energizing the condition sensing apparatus.
In a tire pressure monitoring system, a pressure sensing device is typically disposed at each tire of the vehicle and a warning device is centrally located at the driver's console to provide a warning whenever the pressure at one or more of the tires deviates significantly from an established norm. Various arrangements are known for energizing the pressure monitoring device where typically a battery is provided at each tire. Other means are also known for energizing these devices such as those disclosed in U.S. Pat. Nos. 4,300,119 and 4,300,120 (where rotation of the tire is utilized to effect energization); U.S. Pat. No. 4,160,234 (where deflation of the tire is utilized); and U.S. Pat. No. 4,263,579 (where power obtained from the main storage battery of the vehicle is utilized). However, these devices are subject to various shortcomings.
Accordingly, it is a first primary object of this invention to provide means for energizing a condition sensing device such as a pressure transducer at a vehicle tire or the like where the requisite energy is transmitted via radio waves from an energy source disposed at the above-mentioned centrally located console or some other centrally located position.
Other tire pressure monitoring patents of interest are U.S. Pat. Nos. 4,048,614; 4,072,927; 4,137,520; 4,237,728; and 4,311,984. The foregoing patents together with the others mentioned above are incorporated herein by reference. The tire pressure monitoring systems disclosed in these patents have various shortcomings due to either the type of pressure transducing device employed or due to the location thereof.
Accordingly, it is a further primary object of this invention to provide improvements with respect to pressure transducing devices for use in monitoring tire pressure or the like, the improvements being with respect to the type of and/or location of the pressure transducer.
It is a further object of this invention to provide improved means for remote energizing a condition (not restricted to pressure) monitoring device.